I would like to bring up 12/2 cable to put a 110 20A electrical outlet on the wall. The house is old and there is not enough space behind the drywall to put a box (it is an outside wall and there are not any outlets in it). In addition, I tried elsewhere on this wall to drill a hole down to the floor below but was unable to get it. So, I'd like to bring up a cable from the floor in front of the wall and install a surface mount box with an outlet. How should I go about this? BX cable? Conduit between floor and box?
The outlet will be for a portable air conditioning unit in the summer and space heater in the winter, thus the sole outlet on the circuit.
Red marking is where I'd like to bring up the cable and install the outlet.
Best Answer
I would use conduit for the run up from the floor
I would run a piece of EMT conduit myself, with a surface mount "handy box" to house the receptacle and a metal old work box with the conduit extending out a KO in its back for holding the junction between the 12AWG stranded THHNs in the conduit and the solid wires of the 12/2 NM-B that is the homerun for this circuit. You'll need a strain-relief cable-clamp in the KO the NM enters the old work box at; inside the box, it's a simple matter of hot to hot, neutral to neutral, and ground to the box ground screw. The receptacle wires up normally (hot to brass, neutral to silver), save for being grounded via its yoke instead of a ground wire as it's in a metal box attached to grounded metal conduit. Drywall anchors can be used for mounting the conduit straps and handy box in this case, by the way.